• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.6
• /
• pp.582-587
• /
• 2008

Structural join is one of the most typical techniques for evaluating XML path queries. Recent researches for structural joins focus on techniques of skipping unnecessary elements using the horizontal distribution information of elements that is indexed on a structure like B+ tree. However, those techniques make the structural join complicated and cannot guarantee efficient join processing due to the overhead of an index structure. In this paper, we propose a new structural join technique that exploits the level information of XML elements. Our technique can skip unnecessary elements using level information, which is vertical distribution information of elements. Through the experimental results, we show that our technique can evaluate structural joins efficiently.

• Journal of KIISE:Databases
• /
• v.30 no.5
• /
• pp.494-506
• /
• 2003

Recently, explosive popularity of multimedia information has triggered the need for retrieving multimedia contents efficiently from the database including audio, video and images. In this paper, we propose an XML-based retrieval scheme and a data model that complement the weak aspects of annotation and conent based retrieval methods. The Property and hierarchy structure of image and video data are represented and manipulated based on the Multimedia Description Schema (MDS) that conforms to the MPEG-7 standard. For audio contents, pitch contours extracted from their acoustic features are converted into UDR string. Especially, to improve the retrieval performance, user's access pattern and frequency are utilized in the construction of an index. We have implemented a prototype system and evaluated its performance through various experiments.

• Journal of Scientific & Technological Knowledge Infrastructure
• /
• s.7
• /
• pp.113-127
• /
• 2001

인용문헌정보의 효율적인 저장과 검색을 위하여 인용한 문헌과 인용된 문헌들의 구성요소를 추출하고 상호 인용관계에 대한 논리정보와 구조정보를 재구성을 통해 표현하고, 패스인코딩 색인기법에 의해 구성요소의 중복을 제거하였으며, 관련 있는 데이터베이스들과의 연계를 위하여 XML을 기반으로 하는 KSCI(Korea Science Citation Index)시스템을 설계하였다.

• Journal of information and communication convergence engineering
• /
• v.7 no.3
• /
• pp.275-280
• /
• 2009

While database(DB) and information retrieval(IR) have been developed independently, there have been emerging requirements that both data management and efficient text retrieval should be supported simultaneously in an information system such as health care, customer support, XML data management, and digital libraries. The great divide between DB and IR has caused different manners in index maintenance for newly arriving documents. While DB has extended its SQL layer to cope with text fields due to lack of intact mechanism to build IR-like index, IR usually treats a block of new documents as a logical unit of index maintenance since it has no concept of integrity constraint. However, In the DB-IR integrations, a transaction on adding or updating a document should include maintenance of the posting lists accompanied by the document. Although DB-IR integration has been budded in the research filed, the issue will remain difficult and rewarding areas for a while. One of the primary reasons is lack of efficient online transactional index maintenance. In this paper, performance of a few strategies for per-document basis transactional index maintenance - direct index update, pulsing auxiliary index and posting segmentation index - will be evaluated. The result shows that the pulsing auxiliary strategy and posting segmentation indexing scheme, can be a challenging candidates for text field indexing in DB-IR integration.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.2
• /
• pp.411-425
• /
• 2000

Information retrieval systems for structured documents which are written in SGML or XML support partial retrieval of document. In order to efficiently process queries based on document structures, low memory overhead for indexing, quick response time for queries, supports to powerful types of user queries, and minimal updates of index structure for document updates are required. This paper suggests the Global Document Instance Tree(GDIT) and proposes an effective indexing scheme and query processing algorithms based on the GDIT. The indexing scheme keeps up indexing and retrieval effciency and also guarantees minimal updates of the index structure when document structures are updated.

• Journal of the Korean Society for information Management
• /
• v.22 no.1 s.55
• /
• pp.105-123
• /
• 2005

The most of all, this study is planned to search an ideal methods to develop the digital library system for our korean ancient books for their safe preservation and, at the same time, for their perusal of transcendental time and space : first. to offer the various access points like traditional oriental Four parts Classics classification, current subject classification and index keyword, etc. : second, to program a digital library system using MARC or XML, but with all bibliographic descriptive elements as possible; third, to prepare the more easy annotated bibliography and index for users' better comprehension, and last, to build original text database for practical reading to avoid the damage of original text. This type of korean ancient books digital library will be developed to the real international bibliographic control by networking enter the same kinds of internal and external organizations.

• Journal of KIISE:Databases
• /
• v.32 no.4
• /
• pp.452-472
• /
• 2005

We propose XIR-Branching, a novel method for processing partial match queries on heterogeneous XML documents using information retrieval(IR) techniques and novel instance join techniques. A partial match query is defined as the one having the descendent-or-self axis '//' in its path expression. In its general form, a partial match query has branch predicates forming branching paths. The objective of XIR-Branching is to efficiently support this type of queries for large-scale documents of heterogeneous schemas. XIR-Branching has its basis on the conventional schema-level methods using relational tables(e.g., XRel, XParent, XIR-Linear[21]) and significantly improves their efficiency and scalability using two techniques: an inverted index technique and a novel prefix match join. The former supports linear path expressions as the method used in XIR-Linear[21]. The latter supports branching path expressions, and allows for finding the result nodes more efficiently than containment joins used in the conventional methods. XIR-Linear shows the efficiency for linear path expressions, but does not handle branching path expressions. However, we have to handle branching path expressions for querying more in detail and general. The paper presents a novel method for handling branching path expressions. XIR-Branching reduces a candidate set for a query as a schema-level method and then, efficiently finds a final result set by using a novel prefix match join as an instance-level method. We compare the efficiency and scalability of XIR-Branching with those of XRel and XParent using XML documents crawled from the Internet. The results show that XIR-Branching is more efficient than both XRel and XParent by several orders of magnitude for linear path expressions, and by several factors for branching path expressions.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.4
• /
• pp.71-78
• /
• 2008

Digital Broadcasting serves a variety of broadcasting services for satisfying the requirement of customers. One of main factors for new broadcasting environment is interoperability between providers and consumers. For this interoperability, metadata standards are proposed for the digital broadcasting and TV-Anytime metadata is one of these standards. On the one hand, there are some researches for efficiently managing the broadcasting metadata on Set-Top Box. This paper proposes the metadata management system for efficiently managing the broadcasting metadata based on the STB which is low-cost and low-setting. Our system consists of a storage engine to store the metadata and an XQuery engine to search the stored metadata and uses special index for storing and searching. We expect that our system will keep the interoperability amongst a variety of applications for broadcasting because we adopts the XQuery for searching the metadata and the XQuery is a standard language for searching XML data.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.11-13
• /
• 2007

There has been much interest in stream query processing. Various index techniques and advanced join techniques have been proposed to efficiently process data stream queries. Previous proposals support rapid and advanced response to the data stream queries. However, the amount of data stream is increasing and the data stream query processing needs more speedup than before. In this paper, we proposed novel query processing techniques for large number of incoming documents stream. We proposed Dissection Technique for efficient query processing in the data stream environment. We focused on the dissection technique in join query processing. Our technique shows efficient operation performance comparing with the other proposal in the data stream. Proposed technique is applied to the sensor network system and XML database.

• Journal of Korea Multimedia Society
• /
• v.7 no.5
• /
• pp.601-616
• /
• 2004

Information retrieval systems for structured documents provide multiple levels of retrieval capability by supporting structure-based queries. In order to process structure-based queries for structured documents, information for structural nesting relationship between elements and for element sequence must be maintained. This paper presents four index structures that can process various query types about structures such as structural relationships between elements or element occurrence order. The proposed algorithms are based on the concept of Global Document Instance Tree.